Dietary Alpha-linolenic Acid Research Articles

Alpha-Linolenic Acid Supplementation Improves Testosterone Production in an Aged Breeder Rooster Model: Role of Mitochondrial Modulation and SIRT1 Activation.

Aging in males can lead to declines in testosterone production, essential for maintaining male reproductive health. To investigate the effects of dietary supplementation with alpha-linolenic acid (ALA) on testosterone production in aged breeder roosters and understand the underlying molecular mechanisms involved. An in vivo model is established to investigate the effects of dietary ALA supplementation on testosterone production in aged breeder roosters, and the Leydig cell culture is used to identify the potential molecular mechanism. Dietary supplementation with ALA increases in plasma testosterone. Congruently, ALA supplementation enhances the expression of testosterone biosynthesis-related enzymes. ALA supplementation exerts anti-apoptotic effects in testicular mitochondria, as evidenced by a lower expression of pro-apoptotic factors and a higher expression of the anti-apoptotic factor B-cell lymphoma 2 (Bcl-2). Moreover, In Leydig cells, ALA supplementation promotes mitochondrial biogenesis genes. The proposed mechanism is that ALA activates the sirtuin1 (SIRT1)pathway and is supported by higher SIRT1 transcript and protein in Leydig cells. Furthermore, blocking SIRT1 with siRNA reverses ALA's effects on testosterone biosynthesis and mitochondrial function-related genes. These findings indicate that dietary supplementation with ALA can improve testosterone production in aged breeder roosters, possibly by modulation of mitochondrial function via activating the SIRT1 pathway.

A higher dietary alpha-linolenic acid intake is associated with lower colorectal cancer risk based on MUC4 rs2246901 variant among Korean adults

Alpha-linolenic acid (C18:3n-3 [ALA]) intake may have a beneficial effect in reducing cancer risk; however, its association with colorectal cancer (CRC) risk remains conflicted. Additionally, ALA was emphasized as being associated with mucins, an important glycoproteins family within the intestine. Thus, we hypothesized that a higher dietary ALA intake may reduce the risk of CRC and this preventive effect has an interaction with mucin 4 (MUC4) rs2246901. We conducted a case-control study at the National Cancer Center in Korea, involving 1039 cases and 1982 controls, aiming to determine the interaction of the MUC4 rs2246901 polymorphism and ALA intake in CRC risk. Dietary ALA intake was collected via semiquantitative food frequency questionnaire (SQFFQ), categorizing by 4 quartiles. We evaluated the odds ratios (ORs) and 95% confidence intervals (CIs) through unconditional logistic regression models. Higher dietary ALA intake was found to be inversely associated with CRC risk (adjusted OR = 0.58; 95% CI, 0.45–0.75, P for trend < .001). No significant association between MUC4 rs2246901 polymorphism and CRC risk was found. In a recessive model, MUC4 rs2246901 seemed to modify this association; participants with at least 1 major allele and higher ALA intake had a significantly lower CRC risk than those who had a lower intake (adjusted OR = 0.56; 95% CI, 0.43–0.72; P interaction = .047). A higher dietary ALA was proposed as a potential protective nutrient against CRC. Moreover, this association might be influenced by presence of the MUC4 rs2246901 polymorphism.

Modification in mitochondrial function is associated with the FADS1 variant and its interaction with alpha-linolenic acid-enriched diet—An exploratory study

Fatty acid desaturase (FADS1) variant-rs174550 strongly regulates polyunsaturated fatty acid (PUFA) biosynthesis. Additionally, the FADS1 is related to mitochondrial function. Thus, we investigated whether changes in mitochondrial function are associated with the genetic variation in FADS1 (rs174550) in human adipocytes isolated from individuals consuming diets enriched with either dietary alpha-linolenic (ALA) or linoleic acid (LA). Two cohorts of men homozygous for the genotype of FADS1 (rs174550) were studied: FADSDIET2 dietary intervention study with ALA- and LA-enriched diets and Kuopio Obesity Surgery study (KOBS), respectively. We could demonstrate that differentiated human adipose-derived stromal cells from subjects with the TT genotype had higher mitochondrial metabolism compared with subjects with the CC genotype of FADS1-rs174550 in the FADSDIET2. Responses to PUFA-enriched diets differed between the genotypes of FADS1-rs174550, showing that ALA, but not LA, -enriched diet stimulated mitochondrial metabolism more in subjects with the CC genotype when compared with subjects with the TT genotype. ALA, but not LA, proportion in plasma phospholipid fraction correlated positively with adipose tissue mitochondrial-DNA amount in subjects with the CC genotype of FADS1-rs174550 in the KOBS. These findings demonstrate that the FADS1-rs174550 is associated with modification in mitochondrial function in human adipocytes. Additionally, subjects with the CC genotype, when compared with the TT genotype, benefit more from the ALA-enriched diet, leading to enhanced energy metabolism in human adipocytes. Altogether, the FADS1-rs174550 could be a genetic marker to identify subjects who are most suitable to receive dietary PUFA supplementation, establishing also a personalized therapeutic strategy to improve mitochondrial function in metabolic diseases.

Dietary alpha-linolenic acid supplementation enhances semen quality, antioxidant capacity, and sperm survival in aging breeder roosters

Aging in breeder roosters is often accompanied by a decline in semen quality, negatively impacting reproductive performance. This study aimed to investigate the effect of dietary alpha-linolenic acid (ALA), an essential omega-3 polyunsaturated fatty acid, on semen quality, antioxidant capacity, and sperm survival in aging breeder roosters. Roosters were divided into 4 groups and fed diets supplemented with 0%, 0.5%, 1%, and 2% ALA for 6 wk. Results indicated significant improvements in semen volume, sperm viability, and sperm density in ALA-supplemented groups compared to the control (P < 0.05). The 1% ALA group exhibited the most notable enhancements in sperm viability and density. Additionally, ALA supplementation increased the activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and reduced malondialdehyde (MDA) levels, indicating enhanced antioxidant capacity (P < 0.05). Furthermore, ALA improved mitochondrial membrane potential (MMP) and reduced early and late sperm apoptosis, with the 2% ALA group showing the highest MMP and the lowest ROS-positive rate (P < 0.05). These findings suggest that dietary ALA supplementation enhances semen quality and antioxidant defenses, and mitigates oxidative stress, thus supporting the reproductive health of aging breeder roosters. This study underscores the potential of ALA as a dietary strategy to improve reproductive efficiency in poultry production.

Dietary n-3 alpha-linolenic and n-6 linoleic acids modestly lower serum lipoprotein(a) concentration but differentially influence other atherogenic lipoprotein traits: A randomized trial

Background and aimsLipoprotein(a) [Lp(a)] is a causal, genetically determined cardiovascular risk factor. Limited evidence suggests that dietary unsaturated fat may increase serum Lp(a) concentration by 10–15 %. Linoleic acid may increase Lp(a) concentration through its endogenous conversion to arachidonic acid, a process regulated by the fatty acid desaturase (FADS) gene cluster. We aimed to compare the Lp(a) and other lipoprotein trait-modulating effects of dietary alpha-linolenic (ALA) and linoleic acids (LA). Additionally, we examined whether FADS1 rs174550 genotype modifies Lp(a) responses. MethodsA genotype-based randomized trial was performed in 118 men homozygous for FADS1 rs174550 SNP (TT or CC). After a 4-week run-in period, the participants were randomized to 8-week intervention diets enriched with either Camelina sativa oil (ALA diet) or sunflower oil (LA diet) 30–50 mL/day based on their BMI. Serum lipid profile was measured at baseline and at the end of the intervention. ResultsALA diet lowered serum Lp(a) concentration by 7.3 % (p = 0.003) and LA diet by 9.5 % (p < 0.001) (p = 0.089 for between-diet difference). Both diets led to greater absolute decreases in individuals with higher baseline Lp(a) concentration (p < 0.001). Concentrations of LDL cholesterol (LDL-C), non-HDL-C, remnant-C, and apolipoprotein B were lowered more by the ALA diet (p < 0.01). Lipid or lipoprotein responses were not modified by the FADS1 rs174550 genotype. ConclusionsA considerable increase in either dietary ALA or LA from vegetable oils has a similar Lp(a)-lowering effect, whereas ALA may lower other major atherogenic lipids and lipoproteins to a greater extent than LA. Genetic differences in endogenous PUFA conversion may not influence serum Lp(a) concentration.

Assessment of omega-3 and omega-6 fatty acid profiles and ratio of omega-6/omega-3 of white eggs produced by laying hens fed diets enriched with omega-3 rich vegetable oil

Abstract The aim of this study was to evaluate the levels of omega-3 (n-3) and omega-6 (n-6) fatty acids in egg and the ratio of n-6/n-3 of white eggs produced by laying hens (Hy-Line white) fed diets enriched with n-3 fats. In this study, alpha-linolenic acid (ALA) levels of the dietary treatments ranged from 0.3 to 6% energy. Grain-based diets containing a low linoleic acid (LA) content were selected to prepare a basal diet to optimize the conversion of ALA into n-3 long chain polyunsaturated fatty acids (LCPUFA). The results showed that the level of all n-3 LCPUFA in eggs improved (P &lt; 0.01) by increasing the levels of dietary ALA. Importantly, eggs produced from laying hens fed diets containing 6%en ALA significantly increased (P &lt; 0.01) the total of n-3 fats by approximately nine-fold. Diets enriched with ALA significantly reduced (P &lt; 0.01) the ratio of n-6/n-3 of the eggs. The n-6/n-3 ratio of eggs decreased from 7.17% in the 0.3%en ALA diet to 1.29% in the 6%en ALA diet. In conclusion, white laying hens fed ALA-enriched diets produced eggs higher in n-3 fatty acids and lower n-6/n-3 ratio, which provides an alternative n-3 rich food for consumers and have beneficial health effects.

Association between dietary omega-3 intake and coronary heart disease among American adults: The NHANES, 1999-2018.

Omega-3 has been extensively studied for its cardiovascular disease (CVD) benefits. However, the results of this evidence are inconsistent. Therefore, in this study, dietary omega-3 intake was investigated further in relation to coronary heart disease (CHD) risk among U.S. adults. We used data from the National Health and Nutrition Examination Survey (NHANES) database for people ages 20 years and older between 1999 and 2018 to conduct a cross-sectional survey. The Medical Condition Questionnaire (MCQ) was used to determine CHD status. We measured dietary omega-3 intake using two 24-hour dietary recall interviews. Multivariate logistic regression and subgroup analysis were used to explore the correlation between dietary omega-3 intake and CHD. The dose-response relationship between the two was analyzed with a restricted cubic spline (RCS). 31,184 study subjects were included, of whom 1,604 (5.14%) were patients with CHD. By quintile (Q) of dietary omega-3 intake, after adjusting for all confounding factors, compared with Q1, when total dietary omega-3, alpha-linolenic acid (ALA), docosapentaenoic acid (DPA), eicosatetraenoic acid (ETA), eicosapentaenoic acid (EPA), and docosahexenoic acid (DHA) intake reached Q5, the odds ratio (95% confidence interval, CI) of CHD were 0.76 (0.60, 0.96), 0.73 (0.57, 0.94), 0.70 (0.54, 0.92), 0.66 (0.50, 0.85), 0.84 (0.69, 1.02), and 0.83 (0.64, 1.07), respectively, while EPA and DHA were not significantly associated with the disease (Trend p > 0.05). Intake of omega-3 and CHD were linearly related (P for nonlinear = 0.603). No significant interactions were found within subgroups except for the age group (P for interaction = 0.001). Sensitivity analysis and multivariate logistic regression results are generally in agreement. Total dietary omega-3, ALA, DPA, and ETA intake were negatively associated with CHD risk. In contrast, EPA and DHA had no significant correlation with CHD.

Predicted essential fatty acid intakes for a group of dairy cows also apply at individual animal level

The ruminant requirements for essential fatty acids (EFAs), particularly linoleic acid (LA) and alpha-linolenic acid (ALA), have not been fully determined, although evidence suggests that an adequate supply of polyunsaturated fatty acids (FAs) could improve immunity and reproduction in transition cows. In previous studies, we predicted EFA intake for a group of cows based on animal characteristics and milk EFA secretions. However, to support precision livestock feeding, we need to match the nutrient requirements and intakes of each cow as closely as possible. Our group-level predictions may not be accurate enough to estimate the EFA intake of an individual cow, due to inter-individual variations in EFA digestion and metabolism related to differences in feed intake, intake patterns, and the composition and functioning of the rumen microbiota. To address this issue, here we set out to establish specific equations that predict EFA intake for an individual cow based on the difference (i.e. the residuals) between observed EFA intake and the predicted EFA intake based on our group-level equations. We studied a database of individual dairy cows (26 experiments; 503 datapoints from three research teams) and we predicted the residuals from (1) dietary and animal-related factors (i.e. full predictions) and (2) animal-related factors only (i.e. field predictions), which are considered more field-amenable. The variance of predicted LA and log ALA intake was explained to 68% by observed LA intake and 66% by observed log ALA intake, respectively. The residuals of LA intake were predicted by dietary ALA content, total FA intake, BW, milk yield and fat content in full predictions, and by BW, feeding level, milk yield and fat content, and sum of milk C4:0 to C14:0 FA in field predictions. The log residuals of ALA intake were predicted by dietary NDF and total FA contents, NDF intake, BW, milk protein, LA and ALA contents, and fat yield in full predictions, and by BW, DM intake, milk LA and ALA contents, and fat yield in field predictions. The field predictions showed a moderate loss of accuracy compared to full predictions based on RMSE of prediction (from 38 to 54 g/d for LA and from 0.090 to 0.12 log (g/d) for ALA). This work is the first to predict the EFA intake of an individual cow based on previously established group-level predictions of EFA intake adjusted for dietary and animal-related factors.

Alpha-Linolenic Acid and Cardiovascular Events: A Narrative Review.

Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize the risk of CVDs is represented by alpha-linolenic acid (ALA), an essential fatty acid of the omega-3 series, known for its cholesterol-lowering effect. The main purpose of this review is to analyze the effects of ALA and investigate the relevant omega-6/omega-3 ratio in order to maintain functionally beneficial effects. Concerning the lipid-lowering preventive effects, ALA may favorably affect the values of LDL-C and triglycerides in both adult and pediatric populations. Furthermore, ALA has shown protective effects against hypertension, contributing to balancing blood pressure through customary diet. According to the 2009 EFSA statement, dietary ALA may contribute to reducing the risk of CVDs, thanks to anti-hypertensive, anti-atherosclerotic and cardioprotective effects.

Differential Association of Dietary Linoleic Acid and Alpha-linolenic Acid with Adipose Tissue in a Sample of Iranian Adults; A Cohort-based Cross-sectional Study.

Overweight and obesity are the most critical risk factors for chronic diseases. The quality of dietary fatty acids as one of the factors affecting fat accumulation has received little attention. This study investigates the association between dietary linoleic acid (LA) and alpha-linolenic acid (ALA) with body fat indices in a sample of healthy Iranian adults. In this cohort-based cross-sectional study, 3,195 individuals aged 20 to 60 who participated in the Shiraz University of Medical Science Employees Health Cohort study were included. Dietary intake was assessed using a validated 118-item Food Frequency Questionnaire (FFQ), and body composition was assessed by the bioelectrical impedance analysis method. Multiple linear regression adjusted for relevant confounders was used to determine the associations. Mean dietary intake of LA was 14.20 ± 7.01 mg/day for men and 13.90 ± 6.71 mg/day for women. Additionally, the daily intake of ALA was 0.18 ± 0.18 mg/day in men and 0.17 ± 0.19 mg/day in women. Dietary intake of ALA for men had an inversely significant association with body fat mass (BFM) (β: -0.585, 95% CI: -1.137, -0.032, P=0.038), percentage of body fat (PBF) (β: -0.537, 95% CI: -0.945, -0.129, P=0.010), Visceral Fat Area (VFA) (β: -2.998, 95% CI: -5.695, -0.302, P=0.029), and Waist to Hip Ratio (WHR) (β: -0.689, 95% CI: -1.339, -0.040, P=0.038). Higher dietary ALA intake was associated with lower BFM, BFP, VAF, and WHR in men. The present study confirms that ALA intake should be considered a preventive treatment to improve body composition. However, further research is recommended in this regard.

Chronic Dietary α-Linolenic Acid Deficiency Alters Dopaminergic and Serotoninergic Neurotransmission in Rats , ,

This study examined the effects of dietary alpha-linolenic acid [18:3(n-3)] deficiency on dopaminergic serotoninergic neurotransmission systems in 60-d-old male rats. Rats were fed semipurified diets containing either peanut oil [the (n-3)-deficient group] or peanut plus rapeseed oil (control group). We measured the densities of the serotonin-2 (5-HT2) receptors and the dopamine-2 (D2) receptors by autoradiography and membrane-binding assays in relation to the fatty acid composition and levels of endogenous monoamines in three cerebral regions: the frontal cortex, the striatum and the cerebellum. Long-term feeding of the (n-3)-deficient diet induced a significantly higher 5-HT2 receptor density in the frontal cortex compared with the control rats without any difference in the endogenous serotonin concentrations. The results also showed some modification of dopaminergic neurotransmission specifically in the frontal cortex in the rats deficient in alpha-linolenic acid, with a significantly lower density of D2 receptors and a significantly lower concentration of endogenous dopamine than in control animals. Moreover, there were lower levels of (n-3) fatty acids in all the regions studied in the deficient rats, balanced by greater levels of (n-6) fatty acids. These results suggest that chronic consumption of an alpha-linolenic acid-deficient diet could induce modifications of the neurotransmission pathways; this might induce the behavioral disturbances previously described in this fatty acid-deficient animal model.

Relationship of Circulating Vegetable Omega-3 to Prognosis in Patients With Heart Failure

BackgroundThere is an urgent need for cost-effective strategies to promote quality of life in patients with heart failure (HF). Several studies reported benefits in HF prognosis for marine omega-3 fatty acids and plant-based dietary patterns. ObjectivesThe aim of this study was to explore whether dietary alpha-linolenic acid (ALA), the main plant omega-3, relates to a better HF prognosis. MethodsALA was determined in serum phospholipids (which reflect long-term dietary ALA intake and metabolism) by gas chromatography in 905 ambulatory patients with HF caused by different etiologies. ResultsAfter a median follow-up of 2.4 years (range: 0.02-3 years), 140 all-cause deaths, 85 cardiovascular (CV) deaths, and 141 first HF hospitalizations (composite of all-cause death and first HF hospitalization, n = 238) were documented. Using Cox regression analyses, we observed that, compared with patients at the lowest quartile of ALA in serum phospholipids (Q1), those at the 3 upper quartiles (Q2-Q4) exhibited a reduction in the risk of composite of all-cause death and first HF hospitalization (HR: 0.61; 95% CI: 0.46-0.81). Statistically significant reductions were observed for all-cause death (HR: 0.58; 95% CI: 0.41-0.82), CV death (HR: 0.51; 95% CI: 0.32-0.80), first HF hospitalization (HR: 0.58; 95% CI: 0.40-0.84), and the composite of CV death and HF hospitalization (HR: 0.58; 95% CI: 0.42-0.79). ConclusionsHF patients with bottom 25% ALA levels in serum phospholipids had a worse prognosis during a mid-term follow-up compared with those with the highest levels. This might be a target population in whom to test dietary ALA-rich interventions to promote quality of life.

Red blood cell omega-3 fatty acids and attention scores in healthy adolescents

Omega-3 fatty acids are critical for brain function. Adolescence is increasingly believed to entail brain vulnerability to dietary intake. In contrast to the abundant research on the omega-3 docosahexaenoic acid (DHA) in cognition, research on DHA and attention in healthy adolescents is scarce. In addition, the role of alpha-linolenic acid (ALA), the vegetable omega-3 fatty acid, is unexplored. We examined associations between DHA and ALA and attention function among a healthy young population. In this cross-sectional study conducted in 372 adolescents (13.8 ± 0.9 years-old), we determined the red blood cell proportions of DHA and ALA by gas chromatography (objective biomarkers of their long-term dietary intake) and measured attention scores through the Attention Network Test. We constructed multivariable linear regression models to analyze associations, controlling for known confounders. Compared to participants at the lowest DHA tertile (reference), those at the highest DHA tertile showed significantly lower hit reaction time-standard error (higher attentiveness) (28.13 ms, 95% confidence interval [CI] = – 52.30; – 3.97), lower hit reaction time ( – 38.30 ms, 95% CI = – 73.28; – 3.33) and lower executive conflict response ( – 5.77 ms, 95% CI = – 11.44; – 0.09). In contrast, higher values were observed in those at the top tertile of ALA in hit reaction time compared to the lowest one (46.14 ms, 95% CI = 9.90; 82.34). However, a beneficial association was observed for ALA, with decreasing impulsivity index across tertiles. Overall, our results suggest that DHA (reflecting its dietary intake) is associated with attention performance in typically developing adolescents. The role of dietary ALA in attention is less clear, although higher blood levels of ALA appear to result in lower impulsivity. Future intervention studies are needed to determine the causality of these associations and to better shape dietary recommendations for brain health during the adolescence period.

Association between dietary intake of n-3 polyunsaturated fatty acids and risk of colorectal cancer in the Japanese population: The Japan Collaborative Cohort Study.

Epidemiological studies of the dietary intake of specific n-3 polyunsaturated fatty acids (PUFA) and anatomical subsite-specific colorectal cancer (CRC) are limited. We examined the prospective associations of total n-3 PUFA, marine-derived n-3 PUFA [combined eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA)], and alpha-linolenic acid (ALA) as plant-derived n-3 PUFA with the risk of CRC by subsite in the Japan Collaborative Cohort Study. The participants completed a self-administered food frequency questionnaire and had no prior history of CRC. Cox proportional hazards model was used to determine the associations between n-3 PUFAs intake and CRC risk overall and by anatomical subsite. During the median 13.8-year follow-up period, 699 of the 42,536 participants aged 40-79 years developed incident CRC. An inverse association was found between dietary ALA intake and the risk of distal colon cancer; the multivariable hazard ratios and 95% confidence intervals for the highest quartiles (Q4) were 0.41 (0.21-0.81; p trend=0.01) compared with the lowest quartiles (Q1). Marine n-3 PUFA intake was not associated with CRC risk in the overall or anatomical subsite-specific analyses. Our findings suggest that higher ALA intake may be beneficial for lowering the risk of distal colon cancer.

PSIV-13 Effects of Increasing Dietary Alpha-Linolenic Acid on Nursery Pig Growth Performance and Response to Immune Challenge

Abstract A total of 350 weanling pigs (Line 241 × 600, DNA; initially 5.8 ± 0.1 lb BW) were used in a 41-d study to evaluate growth performance and immune response of nursery pigs fed diets containing increasing levels of O3 Trial Feed, a source of omega-3 fatty acids (alpha-linolenic acid). At weaning, pigs were randomly assigned to 1 of 5 dietary treatments in a completely randomized design with 5 pigs per pen and 14 replications per treatment. The dietary treatments included increasing percentages of O3 Trial Feed (0, 1, 2, 3, and 4%). Omega-6:3 ratios for the 5 treatments within each phase were: Phase 1 (27.3:1, 11.6:1, 7.4:1, 5.4:1, 4.3:1); Phase 2 (23.0:1, 9.6:1, 6.1:1, 4.5:1, 3.6:1); and Phase 3 (24.4:1, 10.2:1, 6.5:1, 4.8:1, 3.8:1), respectively. On d 25, two pigs per pen were injected with 20 µg of Escherichia coli (E. coli) lipopolysaccharide (LPS) per kg BW and 1 pig per pen was injected with saline to serve as a control. Body temperature was recorded from the 3 pigs per pen prior to the injection (hour 0) and 2, 4, 6, and 12 h after injection. On d 25 a blood sample was collected 4 h post injection from pigs injected with the LPS challenge to determine IL-1β levels in serum. For overall growth performance, there were no differences observed in ADG, ADFI, or G:F (P &amp;gt; 0.05). Temperature increased at 2 h post LPS injection, then decreased as time from the LPS injection increased (main effect of time, P &amp;lt; 0.0001). Dietary treatment did not influence change in body temperature or IL-1β (P &amp;gt; 0.05). In this study, dietary alpha-linolenic acid levels did not influence growth performance or immune response to a LPS challenge.

Dietary Alpha-Linolenic Acid Supports High Retinal DHA Levels.

The retina requires docosahexaenoic acid (DHA) for optimal function. Alpha-linolenic acid (ALA) and DHA are dietary sources of retinal DHA. This research investigated optimizing retinal DHA using dietary ALA. Previous research identified 19% DHA in retinal phospholipids was associated with optimal retinal function in guinea pigs. Pregnant guinea pigs were fed dietary ALA from 2.8% to 17.3% of diet fatty acids, at a constant level of linoleic acid (LA) of 18% for the last one third of gestation and retinal DHA levels were assessed in 3-week-old offspring maintained on the same diets as their mothers. Retinal DHA increased in a linear fashion with the maximum on the diet with LA:ALA of 1:1. Feeding diets with LA:ALA of 1:1 during pregnancy and assessing retinal DHA in 3-week-old offspring was associated with optimized retinal DHA levels. We speculate that the current intakes of ALA in human diets, especially in relation to LA intakes, are inadequate to support high DHA levels in the retina.

Dietary omega-3 polyunsaturated fatty acid and alpha-linolenic acid are associated with physical capacity measure but not muscle mass in older women 65–72 years

PurposeThe aim was to investigate the cross-sectional association of dietary omega-3 polyunsaturated fatty acids PUFA (alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)) intake with multiple physical functions, muscle mass and fat mass in older women.MethodStudy subjects were 554 women from the Osteoporosis Risk Factor and Prevention Fracture Prevention Study, with dietary intake assessed with 3-day food record. Body composition was measured by dual-energy X-ray absorptiometry. Physical function measures included walking speed 10 m, chair rises, one leg stance, knee extension, handgrip strength and squat. Short physical performance battery (SPPB) score was defined based on the European working group on sarcopenia criteria.ResultsThe multivariable adjusted models showed statistically significant associations for dietary ALA with higher SPPB (β = 0.118, P = 0.024), knee extension force at baseline (β = 0.075, P = 0.037) and lower fat mass (β = − 0.081, P = 0.034), as well as longer one-leg stance (β = 0.119, P = 0.010), higher walking speed (β = 0.113, P = 0.047), and ability to squat to the ground (β = 0.110, P = 0.027) at baseline. Total dietary omega-3 PUFA was associated with better SPPB (β = 0.108, P = 0.039), one-leg stance (β = 0.102, P = 0.041) and ability to squat (β = 0.110, P = 0.028), and with walking speed (β = 0.110, P = 0.028). However, associations for dietary EPA and DHA with physical function and body composition were not significant.ConclusionDietary omega-3 and ALA, but not EPA and DHA, were positively associated with muscle strength and function in older women. The intake of omega-3 and its subtypes was not associated with muscle mass. Longitudinal studies are needed to show whether omega-3 intake may be important for muscle function in older women.

Effects of plant-based versus marine-based omega-3 fatty acids and sucrose on brain and liver fatty acids in a mouse model of chemotherapy

ABSTRACT Chemotherapy can result in toxic side effects in the brain. Intake of marine-based omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), alter brain fatty acids, potentially improving brain function. However, it is unclear if alpha-linolenic acid (ALA), the plant-based n-3, affects brain PUFAs during chemotherapy. The objective of this study was to examine the effects of dietary ALA, EPA and DHA, with high or low sucrose, on brain PUFAs in a mouse model of chemotherapy. Secondarily, the use of liver PUFAs as surrogate measures of brain PUFAs was examined. Lipid peroxidation (4-HNE) and neurotrophic markers (BDNF) were assessed. Female C57Bl/6 mice (n = 90) were randomized to 1 of 5 diets (high EPA + DHA/high or low sucrose, high ALA/high or low sucrose, or control with no EPA + DHA/low ALA/low sucrose) and injected with doxorubicin-based chemotherapy or saline. Brain EPA and DHA were greater (p < 0.0001) with high EPA + DHA diets, regardless of sucrose; there were no significant differences in brain PUFAs between high ALA diets and control. Chemotherapy-treated mice had higher brain and liver DHA (p < 0.05) and lower brain and liver linoleic acid (p < 0.0001). Brain n-3 and n-6 PUFAs were strongly correlated with liver n-3 (r = 0.8214, p < 0.0001) and n-6 PUFAs (r = 0.7568, p < 0.0001). BDNF was correlated with brain total PUFAs (r = 0.36; p < 0.05). In conclusion, dietary ALA in proportions approximately two times greater than consumed by humans did not appreciably increase brain n-3 PUFAs compared to low ALA intake. Liver PUFAs may be a useful surrogate marker of brain PUFAs in this mouse model.

Dietary intake and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of cohort studies

ObjectiveTo examine the associations between dietary intake and tissue biomarkers of alpha linolenic acid (ALA) and risk of mortality from all causes, cardiovascular disease (CVD), and cancer.DesignSystematic review and meta-analysis...

Effect of increased levels of dietary α-linolenic acid on the n-3 PUFA bioavailability and oxidative stress in rat.

We investigated the impact of increased alpha-linolenic acid (ALA) dietary levels on its plasma bioavailability and its bioconversion in n-3 long chain poly unsaturated fatty acids during a 60-d kinetics and the oxidative stress potentially associated. Rats were submitted to a normolipidic diet providing 0, 3, 10 and 24% ALA of dietary lipids for 0, 15, 30 and 60 days. The lipid peroxidation and oxidative stress (nitric oxide (NO) contents and catalase (CAT), superoxide dismutase (SOD), gluthation peroxidase (GPx) activities) were studied in the liver and plasma. When the diet was deprived in n-3 PUFAs, ALA, (eicosanoic acid) EPA and docosahexaenoic acid (DHA) levels decreased in all lipid fractions of plasma and in red blood cell (RBC) lipids. The addition of ALA in the diet linearly improves its bioavailability and its bioconversion in EPA (R²=0.98). By providing 10 to 24% ALA in dietary lipids (LA/ALA, 1·6 and 5·5 respectively), ALA and EPA were more broadly packaged in all lipid fractions (triglyceride (TAG), cholesterol ester (CE) and free fatty acids (FFA)) of plasma from 15 to 30 days timeframe. Only 3% ALA was sufficient to promote the maximal bioconversion of ALA in DHA in phospholipid (PL) and TAG fractions. Additionally, the improvement of ALA bioconversion in EPA and DHA did not impact the oxidative stress markers and limiting lipid peroxidation. To conclude, this study demonstrated that in rat, 10% ALA in the lipid diet for 15-30 days promotes its bioavailability and its bioconversion and allowed the greatest levels in plasma and RBCs.